Doubled over with labour pains, a bewildered Sharifa Um Hamad was convinced she would die.

A child bride at 14, she had never been to school or been told what would happen during the birthing process. She knew only that her swollen belly meant she was pregnant.

Petrified when her waters broke, she walked for kilometres across sand dunes until she reached the concrete prefab building where she had heard kindly strangers were equipped to treat the sick.

There, in the simple hut powered by a single generator, she found Dr Marian Kennedy and sobbed in her arms in terror. The doctor - known as Mariam to the Bedu who sought her expertise - instantly allayed her fears with four simple words.

"Consider me your mother," she told the teenager.

"I thought the baby would come out of my mouth," Um Hamad now recalls. "I had no idea what labour pains were or what was happening to me. But Dr Mariam explained the birthing process to me, showed me how to look after the baby and taught me how to breastfeed. Even then I was scared because I thought the baby was trying to eat me."

That was nearly four decades ago and not only has Um Hamad, now 52, had 11 more children since, but that first baby, Sheikha, is now a 38-year-old schoolteacher - and just one of the success stories of the Oasis Hospital in Al Ain.

When it was founded in 1960 under the patronage of Sheikh Zayed and his brother Sheikh Shakhbut, the healthcare of the emirate was in dire straits.

Only 50 per cent of babies survived and one in three mothers died during childbirth. Malaria and tuberculosis were rife while facilities in the desert were rudimentary at best. Crude birthing methods, such as using rock salt to treat bleeding in new mothers, often left them infertile or battling potentially lethal infections.

This month, the hospital celebrates its 50th anniversary with an astonishing legacy for such a relatively short time - overseeing the births of more than 90,000 babies, including several members of the royal family, such as Sheikh Mohammed bin Zayed and Sheikh Saif bin Zayed; slashing the infant mortality rate to less than one per cent; and providing accessible healthcare to thousands of Bedu who had to previously fend for themselves in the desert.

By 2012, the hospital is expected to expand, with a Dh300 million hi-tech centre that will quadruple the number of beds.

"Many of the rulers today might not have been born if it were not for the Oasis," says David Printy, the hospital's chief executive. "The health conditions back then were similar to Afghanistan today. The population was in decline because of disease and death. The conditions were terrible."

What changed the course of the history of medicine in the UAE was the impetus from the two sheikhs to provide adequate healthcare for their community.

They had been impressed by facilities at American-run hospitals they had visited in Bahrain and Muscat in the 1950s and were keen to match their standards on home turf.

On November 20, 1960, the American Dr Kennedy arrived with her husband, Pat, also a doctor, and their young children Kathleen, Nancy, Scott and Douglas. They were later joined by other Christian missionaries from the US and Canada.

The Kennedys set up base in a mud-block guest house donated by Sheikh Zayed and had not even unpacked when their first maternity patient arrived two days later. Aptly, the baby was called Mubarak, meaning the blessed, and word soon spread among the neighbouring villages.

Patients would travel for days by camel, donkey and on foot to see "Kenned" and "Mariam", camping on the grounds until they could be seen and offering to pay with animals and eggs when they lacked financial means. Often the sheikhs would foot the medical bill, a legacy that continues to this day. "We are the only hospital we know of that does not refuse patients," says Printy.

Within two months, there were more than 200 patients arriving every morning from as far afield as Oman, while 1,000 were registered as outpatients. By the end of the fifth year, the number of outpatients had grown to 20,000.

The hospital soon outgrew its tiny headquarters. Heavy rain damaged the mud compound in March 1963, so the clinic was moved to a new prefabricated building, which burnt down six months later. It was replaced with a concrete building in 1964, with a labour and delivery suite, X-ray facilities and en suite patient rooms following in the 1970s.

Today, the hospital has 47 doctors of 30 different nationalities and boasts 50 private rooms, each with an en suite majlis to allow families to visit. When a baby is born, the rooms are frequently filled with flowers and platters of food and fruit as hundreds of extended family members come to see the new arrival.

While less than 15 per cent of the population is Emirati, that is not reflected in the patients who flock to the Oasis. Forty-three per cent are nationals, many second and third-generation since the founding of the UAE, whose families have a long-standing association with the Kennedys.

Daghaish al Kalbani, 36, was born in the Oasis and five of his six children have followed in his footsteps. He recalls his first experience of the hospital. "I had a terrible fever when I was six years old but the trip from our house in Al Ain took two-and-a-half hours because there was no road," he says.

"There were small rooms made of bamboo. People were suspicious of the strangers at first but after the Kennedys travelled around to tell people about the hospital, they won our trust. They were like members of the family in the end. People came from all over the Emirates to be treated - everyone loved them."

The original missionaries have long since left and it is now up to Abu Dhabi's government to preserve their legacy and keep developing the site. Marian Kennedy returned to the US in 1975 and died two years ago, eight years after her husband. The Canadian nurse Gertrude Dyck, the longest-serving staff member who wrote a history of the hospital called The Oasis, died last year.

Nancy Brock, who worked as a nurse for 35 years and was known as Aneesa before retiring to Canada in 2005, says: "The hospital changed immensely in the time I was there. When I arrived in 1970, all medicines had to be brought into the country and there were a lot of superstitions. Many times, people refused surgery out of fear when it could have helped and even cured them.

"I loved my job and Arab hospitality meant I often had coffee and dates with them while I was teaching patients. I was also invited to homes frequently, especially if I had delivered a baby in the family. We were a part of the community."

The coming months will see space for another 140 beds being created as well as a dedicated children's wing, general surgery, an intensive care unit and a new labour and delivery suite, enabling it to cope with 5,000 births a year compared to the current 3,400.

While progress is welcomed, there is fear in the community that the hospital that once doubled as a social centre could lose the personal touch.

Al Kalbani sighs. "Before I felt we were closer to the doctors and nurses and when we turned up, we would be seen within minutes," he says. "Now you have to wait for them to put your information into the computer and for your number to be called."

And Um Hamad adds: "It used to be a social visit but it is not anymore."

Printy, however, says he is determined to maintain the hospital's unique ties with the community and its patients' sense of ownership. "We have been here since the beginning and are here to serve the community," he says. "We have a rich history but we are very modern. The hospital has a distinct personality and healthcare is delivered with love and passion."

The Kennedys' daughters Kathleen and Nancy will return to Al Ain on Wednesday for an anniversary celebration featuring a camel procession and military displays.

"You cannot imagine the depth of emotion attached to our childhood there," says Kathleen Kennedy Quadro. "These people are among the most gracious, generous, hospitable people in the world and warmly welcomed us into their community."

She is particularly looking forward to a reunion with Sheikh Mohammed bin Zayed, the Crown Prince of Abu Dhabi, who is expected to attend the festivities as the first royal family member to be born at the Oasis with the help of her parents.

And when he returns to his birthplace, the words he once uttered to the Kennedys - "If you had not come, we would not be here" - will carry a special resonance.

Timeline

April 1960 Drs Pat and Marian Kennedy visit Sheikh Zayed and Sheikh Shakhbut to choose a site for a hospital in Al Ain. Pat Kennedy is unexpectedly called upon to deliver a royal baby, delighting the family with his calm and professional manner.

1960 The Kennedys move to the UAE on November 20 and deliver their first baby, Mubarak, two days later. A mud-block guest house is their first base.

1963 Heavy rain destroys the guest house so patients are moved into eight new prefabricated rooms, made of palm branches and corrugated aluminium, on the present site in March. The new quarters are destroyed by fire in October.

1964 The first concrete hospital is built with 20 rooms and inpatient facilities.

1965 770 babies are born, compared with 67 in 1961. The population of Al Ain, just 1,800 when the Kennedys moved there, surges dramatically as healthcare improves. Today it is 374,000.

1975 The Kennedys return to the US in June and Dr Larry Liddle and his wife, Marilyn, a nurse, arrive.

1976 Dr Daryl Erickson, the hospital’s first surgeon, arrives.

1984 Work begins on a new 50-bed inpatient centre, which still exists.

1994 The outpatient facility is completed and later named the Dr Fouad clinic, after Dr Liddle’s Arabic nickname.

2000 Pat Kennedy dies at his home in California.

2005 Marian Kennedy receives one of the inaugural Abu Dhabi Awards, presented by Sheikh Mohammed bin Zayed, the Crown Prince she helped deliver at the Oasis.

2007 The Oasis is the first private facility in Abu Dhabi to receive the Joint Commission International Accreditation, a US-based standard of healthcare.

2008 Marian Kennedy dies in July. The birthing suite is renamed the Kennedy Center for New Life with Sheikh Hamed bin Zayed in attendance.

2009 Gertrude Dyck, the Canadian nurse and author of The Oasis, dies after a fall at her home.

2012 A new wing is due to open with 140 more beds, a children’s section, an intensive care unit and a delivery suite.